Fiber optic cables carry optical fibers capable of transmitting optical voice, video, and data signals with greater bandwidth than electrical cables. As businesses and households demand increased data capacity, fiber optic telecommunications networks based on fiber optic cables are displacing conventional wire-based electrical voice, video, and data signal carriers.
Fiber optic cables used in telecommunications networks can include multiple optical fibers. One such fiber optic cable includes an outer jacket that contains a plurality of loose buffer tubes that each contain one or more loosely arranged optical fibers. Such cables are capable of optically transmitting large amounts of data over the optical fibers and are typically designed as trunk cables for optical telecommunications networks. The looseness of the buffer tubes and the optical fibers within allow the fiber optic cable to be bent, twisted and otherwise manipulated without imparting substantial strain on the buffer tubes and the optical fibers carried within.
When such fiber optic cables are used in a telecommunications network, they need to be connected to optical fiber connectors, such as one or more multifiber connectors. Multifiber connectors are used to interface the optical fibers carried in the cable with other equipment in the telecommunications network, such as a connector module in a data center. Connecting the optical fibers to a multifiber connector usually involves separating (furcating) the buffer tubes at a furcation point, accessing the optical fibers within the buffer tubes, and then connecting the ends of the optical fibers to the multifiber connector.
If the optical fibers carried in loose buffer tubes are connected directly to a multifiber connector without first being immobilized at the furcation point, their movement can adversely impact the performance of the connectorized cable assembly and even cause system failures. For example, changes in the relative lengths of the buffer tubes and the fibers carried within can impart strain to the optical fibers, and this strain can be communicated to the multifiber connector. It is therefore important to ensure that the optical fibers carried by the cable are immobilized at the furcation point when connecting the optical fiber ends to one or more multifiber connectors.
Furcation methods involve cutting the buffer tubes, then sliding furcation tubes over exposed optical fiber end portions while leaving a small gap between the buffer tube end and the furcation tube end so that a portion of the optical fibers are exposed. The furcation tubes are then attached to the exposed optical fiber portions and to the buffer tubes using an epoxy, thereby immobilizing the optical fibers at the furcation point. While the optical fibers are loosely held in the furcation tubes, their being immobilized at the furcation point keeps the length of the optical fibers and the furcation tubes roughly equal over the relatively short length of the furcation tubes, thereby reducing or preventing stress in the fibers within the cable from being transferred into the connector. A furcation jacket is then arranged at the furcation point to cover the epoxied furcation tubes, buffer tubes and optical fibers for added support and protection. Once these steps are performed, the entire assembly needs to remain in a fixed, vertical position while the epoxy cures. While effective, this fiber optic cable furcation method is time consuming and labor intensive.